Coating applying apparatus



July 16 1963 c. F. scHAEFER 3,097,968

comme APPLYING APPARATUS INVENTOR CHA/i255 /L JHHfFeR July 16, 1963 c.F. scHAEFER 3,097,958

COATING APPLYING APPARATUS Filed Nov. 25, 1960 2 Sheets-Sheet 2 INVENTOR(HH/HES f cwEFE/ United States Patent 3,097,968 COATING APPLYINGAPPARATUS Charles Frederick Schaefer, 94 Botsford Place, Trumbull, Conn.Filed Nov. 25, 1960, Ser. No. 71,713 9 Claims. (Cl. 118-259) Thisinvention relates generally to Iapparatus for applying coatings, suchas, adhesives, particularly rubber and other cements containingsolvents, to sheet or Slab materials.

`Coating applying machines exist in which a coating roller and a coatingcontrol roller are rotatably mounted side-by-side, and the supply ofadhesive or other coating substance is contained between the coating andcoating control rollers above the line of rollin-g contact therebetweenso that, as such rollers are rotated, the surface of the coating rollerpicks up a lilm of adhesive from the supply for transfer to the sheet orslab material conveyed past the rotated coating roller. A machine of thedescribed character has the advantage of eliminating the adhesiveholding tank or reservoir which is normally provided in addition to thecoating and coating control rollers, but difiiculties -are experiencedin containing the supply of the adhesive or other coating substance =atthe ends of the rollers, particularly when lluid liquid adhesives areemployed. Some existing machines have radially outward extending flangesat the ends :of the coating control roller which closely engage the endsurfaces of lthe coating roller -to actas Scrapers and as :dams at theopposite ends of the supply of adhesive. However, such `ilanges do notprovide a permanently effective seal for containing the supply ofadhesive at the ends .of the rollers 1by reason of the wear of theflanges and of the end surfaces of the coating roller, particularly whenthe latter is formed of rubber. Other existing machines have steelplates Idisposed against the ends of the rollers, but such plates arelalso subject to excessive wear and thus are ineffective to preventdripping of the supply of `adhesive between the rollers and the endplates.

Further, the space between the coating and coating control rollers abovethe line of rol-ling contact therebetween can only contain a limitedquantity of adhesive, so that frequent refilling of such space isrequired. Attempts to increase the capacity of the space for the supplyof adhesive by increasing the diameters of the rollers are notsatisfactory by reason of the increased cost of such large diameterrollers, and further by reason of the fact that, if the Iadhesive is inya solvent, the large lsurface areas of the large diameter rollersexpose correspondingly large quantities of the adhesive solution toevaporation of the solvent, so that the adhesive in the supply tends tothicken. It then becornes necessary to add solvent to the supply of`adhesive contained between the rollers and, since the solvent does notreadily mix with the adhesive, the 4adhesive applied to the sheet orslab materials will be of non-uniform consistency.

The problem of evaporation of the solvent from the adhesive solutioncontained between the `rollers cannot be conveniently solved by theprovision of an airtight hood enclosing the rollers because of the needto frequently add adhesive to the supply contained between the rollers.

Accordingly, it is `an object of this invention to provide an adhesiveapplying apparatus of the type having a supply of adhesive contained inthe space above the line of rolling contact between a coating roller andIa coating control roller, and wherein improved means are provided forcontaining the adhesive within such space at the ends of the rollers.

Another object is to provide `an adhesive applying apparatus of thedescribed character wherein a constant Patented July 16, 1963 quantityof adhesive solution is maintained in the space between the coating `andcoating control rollers by the continuous circulation of adhesivesolution between that space and a relatively large capacity storage tankor container.

A further object is to provide an adhesive applying apparatus of thedescribed character wherein the adhesive solution in the storage tank orcontainer is continuously mixed or agitated and solvent can lbe addedthereto, as required, so as to maintain a uniform consistency of theadhesive solution as sol-vent evaporates therefrom during exposure tothe atmosphere at the surfaces of the rollers and at the supplycontained between the rollers.

In accordance with an -aspect of this invention, an adhesive applyingapparatus has end plates pressed towards the end surfaces of the coatingroller and the coating con trol roller, and such plates carry lsealingmembers which may ybe formed of any suitable material, preferablyTeflon, that is, polytetrauoroethylene, or the like, and which engagethe end surfaces lof the rollers to provide an effective seal againstthe leakage of adhesive out of the space between the rollers even whenthe adhesive is of relatively low viscosity.

In accordance with another aspect of the invention, one ofthe end plateshas an overow opening therein to determine the level of the adhesivesolution in the space between the rollers, and the adhesive solution iscontinuously supplied to such space by way of a supply pipe extendingfrorn a relatively large capacity tank or lreservoir -to which adhesivesolution is returned after overflowing from the space between therollers.

In accordance with another aspect of the invention, means are providedfor adding solvent to 4the adhesive in the large capacity tank orcontainer in which the added solvent and adhesive can be thoroughlymixed so yas to ensure that the adhesive applied by the coating rolleris of uniform consistency.

In an .adhesive applying apparatus embodying this invention, the coatingroller, when formed with -a rubber or other resilient surface, isfurther provided with metal end disks of the same diameter as the rollerand which are slidlably engaged by the sealing elements carried by theend plates so as to maintain the uniform axial lengths of the coatingand coating control rollers necessary to the effective sealing of theends of the -space containing the supply of adhesive between the coatingand coating control rollers.

The above, and other objects, features `and advantages of the invention,will be apparent in the following detailed description of yadhesiveapplying apparatus embodying this invention which is to be read inconnection with the accompanying 'drawings forming a part hereof, andwhere- 1n:

FIG. 1 is a front elevational view of an adhesive .applying apparatusembodying the prese-nt invention;

FIG. 2 is an enlarged vertical sectional view taken along the line Z-Zof FIG. 1;

FIG. 3 is an enlarged detail view showing a modification of theapparatus illustrated in FIG. 1;

FIG. 4 is an enlarged vertical sectional view taken along the line 4 4of FIG. l;

FIG. 5 is a fragmentary detail View showing la modification of a portionof the structure illustratted in FIG. 4; FIG. 6 is an enlarged sideelevational View of the apparatus shown in FIG. 1; and

FIG. 7 is a side elevational view of the apparatus shown in FIG. 1, butas viewed from the end opposite to that shown in FIG. 6.

Referring to the drawings in detail, -it will be seen that an adhesiveapplying apparatus embodying the invention :and there generallyidentified by the reference numeral 10 includes a coating roller 12 anda coating control roller 3 14 (FIG. 4) which are rotatably supported inside-by-side relationship and with their axes spaced apart so that thesurfaces of -r-ollers 12 and 14 are substantially in rolling cont-actwith each other along a horizontal line to define a space 16 thereabovefor accommodating a supply of adhesive or other coating substance.

In the apparatus 10, the coating roller 12 includes an axle 18 having arigid metal body 20 thereon and a rubber or other resilient cover 22extending around body 20. Stainless steel or other har-d metal disks 24(FIG. 1) having the same diameter as the outer surface of rubber cover22 are disposed at the opposite ends of roller 12 and secured to thebody thereof, for example Vby screws 26 (FIG. 4). The end portions ofaxle 18 extend substantially beyond end disks 24 of roller 12 and arejournalled in suitable fixed bearings 28 (FIG. 2) provided in supportmembers 30 and 32.

The coating control roller 14 preferably has a diameter substantiallysmaller than the diameter of coating roller 12 and may include a metalbody 34 (FIG. 4) fixed on an axle 36. The opposite end portions of axle36 project substantially beyond body 34 and are journalled in bearingblocks 38 which are slidable along horizontal guideways 40 formed insupport members 30 and 32 so that coating control roller 14 may be movedtoward and away from coating roller 12 by displacing the Ibearing blocks38 along the related guideways 40. In order to effect adjustment ofbearing blocks 38, each of the support members 30 and 32 has anadjusting screw 42 extending threadably through a tapped bore in thesupport member into the related guideway 40 and being rotatablyconnected to the bearing block 38 in the -latter so that rotation ofscrew 42 causes displacement of the related bearing block along theguideway 40. It will be apparent that the adjusting screws 42 providemeans by which the parallelism of the Iaxes of Irotation of rollers 12and 14 may be adjusted, and also by which the contact pressure ofcoating control roller 14 against the rubber surface 0f coating roller12 may be adjusted.

As is represented by the arrows on FIG. 4, rollers l12 and 14 arerotated in opposite `directions so that the surfacesof such rollers movedownwardly past the supply of adhesive in space 16, thereby to pick-upfilms or coating of adhesive from such supply, and the film or coatingof adhesive picked up by coating roller 12 is then transferred to sheetor slab material S which is conveyed past the bottom of roller 12. Therotational speeds of rollers 12 and 14 are preferably related to eachother so that the surface speed of roller 12 is substantially greaterthan the sur-face speed of roller 14, thereby providing a wiping actionwhich prevents the build-up of an excessive thickness of adhesive oncoating roller 12. Further, the thickness of the film or coating ofadhesive picked up from the supply by coating roller 12 and transferredfrom the latter to the material S is controlled by varying the contactpressure of roller `14 against roller 12, for example, by manipulationof .adjusting screws 42.

The apparatus embodying this invention further includes at least onepressure or back-up roller disposed below coating roller 12 to supportthe material S during the application of adhesive to the latter. Theillustrated apparatus y10 has two pressure or back-up rollers 44 onaxles 46 which project beyond their opposite ends and are journalled inbearing `blocks 48 carried by side frame members 50 and 52. -In order toaccommodate material S having different thicknesses, coating roller 12and pressure or back-up rollers 44 are vertically adjustable relative toeach other. Such adjustment may be effected by vertically adjusting thepressure or back-up rollers 44 while coating roller 12 and coatingcontrol roller 14 are vertically fixed, or, 4as in the apparatus 10illustrated in the drawings, the axes of pressure rollers 44 may befixed, While coating roller 12 and coating control roller 14 arevertically adjustable as a unit. In apparatus 10, support members 30land 32 have jack screws S4 and 56, respectively, depending therefromand being vertically slidable in bores formed `in side `frame members 50and 52 and in guide brackets 58 and 60 depending from the side framemembers. An adjusting nut 62 is `screwed on each of the jack screws 54and 56 and rests on a suitable thrust bearing `64 carried by the relatedguide bracket 58 or 60 so that the jack screws 54 and 56, and therelated support members 30 and 32 are vertically displaced in responseto rotation of adjusting nuts 62. In order to effect the joint verticalmovement of jack screws 54 and 56, each adjusting nut 62 has a wormwheel formed in the outer peripheral surface thereof and meshing with aworm 66 (FIGS. 2 and 4) secured on a common laterally extending shaftwhich has its opposite end portions journalled in bearings carried byguide brackets 58 and 60. A hand crank 70 (FIG. l) is secured on one endof shaft 68 at the outside of the adjacent frame member 50 to permitmanual rotation of shaft 68. Thus, the adjusting nuts 62 may besimultaneously rotated to effect either raising or lowering of supportmembers 30 and 32, thereby to either increase or decrease the spacingbetween coating roller 12 and pressure rollers 44 for accommodatingeither thicker or thinner materials S.

In order to drive the `rollers 12, 14 and 44 of apparatus 10, the latterfurther may have a stub shaft 72 projecting from the outside of sideframe member 50 and journalled in a suitable bearing carried by thelatter, with a drive sprocket 74 on shaft 72 being rotated by a suitablydriven drive chain 76 (FIGS. l and 6). A spur gear 78 is also mounted onshaft 72 for rotation with the latter and meshes with a gear 80 securedon the adjacent end of the shaft 46 of one of the pressure rollers 44.The pressure rollers 44 `are made to simultaneously rotate in the samedirection by sprockets 82 (FIGS. l and 7) which are secured on the endsof both shafts 46 adjacent side frame member 52 and which are engaged bya drive chain 84.

Shaft 72 further carries a sprocket 86 (FIG. 6) which drives a chain 88running around a sprocket 90 on the `adjacent end of shaft 18 of thecoating roller and also around a tensioning sprocket 92. As shown inFIG. 6, tensioning sprocket 92 is freely rotatable on a pin 94 carriedby an arm 96 which is pivoted, as at 98, on side frame member 50, andwhich is yieldably urged by a spring 100 in the direction formaintaining the desired tension in chain 88, whereby coating roller 12is `also driven from shaft 72 while permitting vertical adjustment ofthe coating roller relative to the pressure or back-up rollers 44. Therotation of coating roller 12 is transmitted to coating control roller14 by means of a relatively small spur gear or pinion 102 fixed on theend of shaft 18 adjacent support member 32 and meshing with a relativelylarger diameter gear 104 fixed on the adjacent end of shaft 36 ofcoating control roller 14. By reason of the above-mentioned relationshipbetween the pitch diameters of gears 102 and 104, the surface specd ofcoating control roller 14 is substantially less than the surface speedof coating roller 12, thereby achieving the previously mentioned wipingaction.

As shown in FIG. 4, the axis of control roller 14 is elevated relativeto the axis of coating roller 12 so that the material S to be coated maybe advanced over a support table 106 extending under coating controlroller 14 and terminating adjacent the rearmost of pressure rollers 44where the sheet or `slab material S is engaged by the rotated coatingroller 12 and pressure rollers 44 for feeding movement through theapparatus while a film or coating of adhesive is applied to the uppersurface of the sheet or slab material.

It will be apparent that the space 16 defined between rollers 12 and 14above the line of rolling contact therebetween can be employed forcontaining a supply of adhesive only if the space 16 is effectivelyclosed at the ends of rollers 12 and 14. In accordance with the presentinvention, end plates 108 and 110 are mounted between the ends ofrollers 12 and 14 and the adjacent support members 30 and 32,respectively (FIGS. l, 2 and 4). In the illustrated adhesive applyingapparatus 10, parallel cross rods 112 extend between the upper portionsof support members 30 and 32, and end plates 108 and 110 are slidablysuspended vfrom the cross rods 112. As shown in FIGS. 2 and 4, endplates 108 and 110 are shaped to project downwardly between the adjacentend portions of shafts 18 and 36, and the inner surface of each of theplates 108 and 110 car-.ries a generally U-shaped sealing element 114formed of any suitable sealing or gasket material, preferably Teflon,that is, polytetr'afluoroethylene, or the like which is suitably securedto the related end plate, for example, by countersunk screws 116. Thesealing elements 114 are shaped and dimensioned so that they extendacross the end surfaces of rollers 12 and 14 at the line of rollingcontact between the latter. Further, plates 108 and 110 are pressedaxially toward the adjacent ends of rollers 12 and 14 so that sealingelements 114 intimately engage the end surfaces of the coating andcoating control rollers, thereby to act as Scrapers Vfor such endsurfaces and to prevent dripping of the adhesive from the ends of space16.

The end plates 108 and 110 may be pressed towards the adjacent endsurfaces of rollers 12 and 14 by screws 118 and 120 (FIGS. l, 2, 4 and6) which extend thread- -ably through suitably tapped holes in supportmembers 30 and 32 and which have their inner ends rotatably connected toplates 108 and 110, respectively, so that screws 118 and 120 can beturned to move the end plates along rods 112 toward the end surfaces ofthe coating and coating control rollers.

Alternatively, as shown in FIG. 3 with respect to end plate 108, each ofthe end plates 108 and 110 can be urged toward the adjacent ends ofrollers 12 and 14 by means of a helical compression spring 122 whichhears, at one end, against the end plate 108 or 110 and has its otherend abutting against a nut 124 adjustable along a threaded pin 126projecting from the adjacent support member 30 or 32. A pin 128 may alsoproject outwardly from end plate 108 or 110 to locate the adjacent endof spring 122.

It will be apparent that, with the arrangement of FIG. 3, the end plates108 and 110 have their sealing elements 114 urged yieldably against theend surfaces of rollers 12 and 14 with forces that may be varied byyadjusting the related nuts 124 along threaded pins 126.

In order to ensure the effective sealing -action of end plates 108 and110 and the related sealing elements 114, it is necessary that rollers12 and 14 be of the same yaxial length and have their end surfaces lyingin the same planes. More specicially, it has been found that theadjacent end surfaces of rollers 12 and 14 must not depart from the samevertical plane by more than .005 inch if the sealing elements 114 are tofunction effectively in scraping the end sur-faces of the rollers and inpreventing dripping of adhesive from space 16. Where the coating roller12 has a rubber cover 22, as in the described ernbodiment of theinvention, the metal end disks 24 of the coating roller resist wearingaway of the ends of roller 12 by frictional contact with sealingelements 114 and thereby ensure the maintenance of the above mentionedequiplanar end surfaces.

It will be apparent that the space 16 for containing the supply ofadhesive has a relatively limited capacity unless rollers 12 and 14 aregiven large diameters. However, large diameter rollers are undesirableboth by treason of the cost thereof and also by reason of the fact thatthe large surface areas of such rollers expose relatively largequantities of the adhesive to the atmosphere for evaporation of solventtherefrom, whereby it becomes necessary to repeatedly add solvent to thesupply of adhesive in the space y16 in order to maintain ta uniformconsistency of the adhesive applied to the sheet or slab material S.Further, since the solvent and adhesive do not mix readily, the additionof solvent directly to the supply of adhesive in the space 16 results inthe coating of the slab or sheet material S with adhesive of non-uniformconsistency. On the other hand, if rollers 12 and 14 have relativelysmaller diameters, resulting in a space 16 of relatively small capacityfor containing the supply of adhesive and which must be more frequentlyrefilled, the evaporation of solvent from the adhesive still constitutesa problem which cannot be solved by the provision of an airtight hoodcovering rollers 12 and 1'4 in view of the necessity for frequentlyadding adhesive to the limited supply thereof in the space 16. It -isalso noted that the frequent manual relling of the space 16 isundesirable as it often results in fthe deposit of an excess quantity ofadhesive in such space which spills over onto adjacent parts of theapparatus and also onto the material S therebelow.

In accordance with the present invention, the supply of adhesive inspace 16 is maintainedat a substantially constant level, thereby makingit possible to employ rollers 12 and 14 which have relatively smalldiameters, and thus are relatively inexpensive, since the capacity ofspace 16 is then of little consequence, and a continuous circulation ofadhesive is maintained to and from space 16 with the necessary additionsof solvent to the circulated adhesive `being made at a location outsideof the space 16 where the solvent and adhesive can be thoroughly mixedso as to ensure the coating of the sheet or slab material S withadhesive of uniform consistency.

In the embodiment of the invention illustrated in FIG. 1, adhesive iscontinuously supplied to the space 16 between rollers =12 and 14 by wayof a supply pipe 130 which terminates in a valved outlet 132 at alocation above space 16. Supply pipe may be secured to the supportmember 32, for example, by a clamping bracket 134 (FIGS. l and 4), andextends from a ilexible supply conduit 136 connected to the outlet pipe138 of an agitator pumping apparatus which is generally identied by thereference 4numeral 140. The agitator pumping apparatus 140 may be of thekind that is commercially available from the Graymills Corporation,Chicago, Illinois, under the designation Model H-5-450'4KE, and whichgenerally includes a motor 142 mounted on a lid 144 adapted to besupported on a tank or container :146 holding a relatively large supplyof adhesive solution. The motor 142 drives a pump 148 which is submergedin the supply of adhesive solution in container 146 and includes aninlet 150 and an outlet i152 connected to the output pipe 138 and alsoconnected to a curved nozzle 154 from which a jet of pumped adhesiveissues in order to produce a swirling agitation within tank or container146. Thus, the mixture of solvent and adhesive in tank or reservoir 146is continuously agitated in order to maintain the uniform consis-tencythereof while adhesive solution is pumped through outlet pipe 138,conduit 136 and supply pipe 130 to the valved outlet 132 `opening abovespace 16.

The maximum height of adhesive solution in space 16 is determined by anoverflow opening 156 (FIG. 2) formed in end plate 108 and having anoverilow pipe 158 extending therefrom. The overflow pipe 158 is, inturn, connected to a return conduit 160 which extends through an openingin lid 144 and is secured to the latter by a Vclamp 162. The pump 148 iseffective to pump adhesive solution into space 16 ata rate that isgreater than that at which the adhesive solution is drawn from space 16by coating roller l12 for application to the sheet or slab material Spassing between roller 12 and pressure rollers 44, so that the level ofadhesive solution -in space 116 always reaches at least to the bottom ofoverflow opening 156 through which the excess adhesive solution overowsinto pipe 158 for return to container or tank 146 by way of returnconduit 160.

Since an excess of adhesive solution is continuously supplied to space16 from supply pipe :130, the capacity of space 16 can be relativelysmall, that is, space 16 can be defined between rollers 12 and 14 ofrelatively small diameters which have the advantage of being relativelyinexpensive and also of presenting relatively small surface aeras atwhich the solvent can evaporate from the -adhesive. However, since somesolvent evaporation will occur, an automatic solvent feed unit 164 isalso preferably provided on the lid 144 and may be of the kind that iscommercially available from the Graymills Corporation, Chicago,Illinois, under the designation Model Al2l75. This solvent feed unitgenerally includes a solvent ,reservoir 166 provided with an off and onvalve control 168 and communicating by way of a pipe 170 with anadjustable metering valve 172 which controls the rate Iof flow or dripof solvent into container or tank 146 from reservoir 166. The meteringvalve 172 is adjusted to provide addition of solvent to the adhesivesolution in container `146 fat a rate that is equivalent to the rate ofevaporation of the solvent from the circulated adhesive. Since thesolvent is added to the relatively large body of adhesive solution incontainer 146 and is there thoroughly mixed with the adhesive prior tobeing pumped through the supply pipe 130, the uniform consistency of theadhesive in space 16 which is applied to the sheet or slab material isensured.

If the coating roller has a rigid surface, as in the case of the coatingroller 12a of FIG. 5, where the metal body 20a forms the surface of thecoating roller, so that the coated sheet or slab material S may adhereto the surface of the coating roller, then the adhesive applyingapparatus may be funther provided with stripping fingers 174 engagingthe surface of coating roller 12a and being suspended from a laterallyextending rod 176 having its opposite ends supported by arms 178projecting from the support members, for example, the support member 32aappearing in FIG. 5.

It Will be apparent that, in adhesive applying apparatus embodying thepresent invention, a continuously replenished supply of solvent adhesiveis maintained in the space 16 between rollers 12 and 14 with theopposite ends of that space 16 being effectively closed by end plates108 and 110 and by the Teflon sealing elements 114 on such end plates.Further, as appears in FIG. 2, the end plates 108 and 110 are spacedfrom the adjacent ends of rollers 12 and 14 by the thickness of thesealing elements 114 so that the adhesive solution can circulate withinthe space between the plates 10S and 110 and the adjacent end surfacesof the rollers to avoid drying or Stringing of the adhesive whichprevents the effective scraping operation of elements 114.

The adhesive applying apparatus embodying this invention furtherfacilitates the cleaning thereof in that water or solvent can be addedto the adhesive in space 16, or a tank of water or solvent can besubstituted for the tank or container 1-46 containing the adhesive,whereupon 0peration of the apparatus causes the solvent or water to becirculated yfor effecting automatic cleaning of rollers 12 and 14 and ofthe end plates 108 and 110. After such automatic cleaning of theapparatus, it is only necessary to elfect a final minimum washing anddrying of the parts of the apparatus normally in contact with theadhesive.

Although adhesive applying apparatus embodying this invention have beendescribed in detail herein with reference to the drawings, it is to beunderstood that other coating substances may be applied by suchapparatus, and that the invention is not limited to those preciseembodiments, but that various changes and modifications may be effectedtherein without departing from the scope or spirit of the invention,except as `defined in the appended claims.

What is claimed is:

l. In an apparatus for applying a liquid adhesive coating substance tosheet or slab material; the combination of a coating roller and acoating control roller of the same length and mounted rotatablyside-by-side with their axes extending horizontally and being spacedapart so as to substantially establish rolling contact therebetweenalong a horizontal line, end plates at the opposite ends of said rollersand extending above said lline of rolling contact, at least one of saidend plates having an overtiow opening therein with the bottom of saidoverflow opening at a level above said line of rolling contact, agenerally U-shaped sealing element having a substantial thickness andbeing secured to the inner surface of each of said end plates, meansacting on said end plates to cause the sealing elements of the latter toslidably bear against the adjacent ends of said rollers, each of saidsealing elements having an inner periphery that extends lacross theadjacent end of said line of rolling contact and then upwardly acrosssaid adjacent ends of the rollers at the opposite sides of said line ofrolling contact thereby defining an upwardly opening recess between saidinner surface of the adjacent end plate and the adjacent ends of therollers so that, when liquid adhesive coating substance is supplied tothe space between said rollers above said line of rolling Contact, theliquid coating substance circulates in each recess to prevent hardeningof the coating substance on said ends of the rollers and said end platesand sealing elements effectively contain the supply of liquid adhesivecoating substance at the ends of said rollers.

2. In an apparatus for applying a liquid adhesive coating substance tosheet or slab material; the combination as in claim l; wherein saidcoating roller has a resilient outer surface portion and wear resistantmetal disks at the opposite ends of the latter for slidable engagementwith said sealing elements.

3. In an apparatus for applying a liquid adhesive coating substance tosheet or slab material; the combination as in claim l, furthercomprising means rotatably driving said rollers with the surfaces of thelatter moving downwardly at said line of rolling contact so that thesurface of said coating roller picks-up a film of liquid adhesivecoating substance from the supply in said space above the line ofrolling contact, and support means below said coating roller forsupporting the material to be coated as the latter is fed under thecoating roller to receive the film of liquid adhesive coating substancefrom said coating roller.

4. In an apparatus for applying a liquid adhesive coating substance tosheet or slab material; the combination as in claim 3, wherein saidmeans acting on said end plates to cause the sealing elements to bearagainst the `adjacent ends of the rollers include screw members whichare adjustable to maintain close sealing engagement between said sealingelements and said ends of the rollers when the contacting surfacesthereof are subject to wear.

5. `In an apparatus for applying a liquid adhesive coating substance tosheet or slab material; the combination as in claim 3, wherein saidmeans acting on said end plates to cause the sealing elements to bearagainst the adjacent ends of the rollers include springs which exertyieldable forces against said end plates in the directions toward saidadjacent ends of the rollers.

6. In an apparatus for applying a liquid adhesive coating substance tosheet or slab material; the combination as in claim 3, wherein saidmeans rotatably driving said rollers rotates said coating roller with agreater surface speed than said coating control roller so that thesurface of the latter exerts a wiping action on the surface of saidcoating roller.

7. In an apparatus for applying a liquid adhesive coating substance tosheet or slab material; the combination as in claim 3, wherein saidcoating roller and coating control roller are fixed in the verticaldirection relative to each other, and further comprising means forvertically ladjusting the clearance between said coating roller andsupport means so as to accommodate material of different thicknesses in`said clearance.

8. In an apparatus for applying a liquid adhesive coating substance tosheet or slab material; the combination as in claim 1, furthercomprising a container for liquid adhesive coating substance, supplyconduit means extending from said container to said space, pumping Iandagitating means operative to mix the liquid Iadhesive coating substancein said container `and to pump the same through said supply conduitmeans imm said container to said space, and return conduit meansextending from said overow opening back to said container.

9. In an apparatus for applying la liquid adhesive coating substance tosheet or slab material; the combination as in claim 8, furthercomprising lmeans operative to add solvent to the liquid adhesivecoating substance in said container to compensate for the solvent lossby evaporation yat said space and the surfaces of the rollers and toensure thorough mixing of the added solvent with the '10 liquid adhesivecoating substance by said pumping and agitating means.

References Cited in the file of this patent UNITED STATES PATENTS2,133,933 Daley -..7- Oct. 18, 1938 2,176,418 Daley Oct. 17, 19392,284,874 Kokay June 2, 1942 2,953,476 Armstrong Sept. 20, 19603,068,837 Shields Dec. 18, 1962 FOREIGN PATENTS 739,054 Great BritainOct. 26, 1955

1. IN AN APPARATUS FOR APPLYING A LIQUID ADHESIVE COATING SUBSTANCE TOSHEET OR SLAB MATERIAL; THE COMBINATION OF A COATING ROLLER AND ACOATING CONTROL ROLLER OF THE SSAME LENGTH AND MOUNTED ROTATABLYSIDE-BY-SIDE WITH THEIR AXES EXTENDING HORIZONTALLY AND BEING SPACEDAPART SO AS TO SUBSTANTIALLY ESTABLISH ROLLING CONTACT THEREBETWEENALONG A HORIZONTAL LINE, END PLATES AT THE OPPOSITE ENDS OF SAID ROLLERSAND EXTENDING ABOVE SAID LINE OF ROLLING CONTACT, AT LEAST ONE OF SAIDEND PLATES HAVING AN OVERFLOW OPENING THEREIN WITH THE BOTTOM OF SAIDOVERFLOW OPENING AT A LEVEL ABOVE SAID LINE OF ROLLING CONTACT, AGENERALLY U-SHAPED SEALING ELEMENT HAVING A SUBSTANTIAL THICKNESS ANDBEING SECURED TO THE INNER SURFACE OF EACH OF SAID END PLATES, MEANSACTING ON SAID END PLATES TO CAUSE THE SEALING ELEMENTS OF THE LATTER TOSLIDABLY BEAR AGAINST THE ADJACENT ENDS OF SAID ROLLERS, EACH OF SAIDSEALING ELEMENTS HAVING AN INNER PERIPHERY THAT EXTENDS ACROSS THEADJACENT END OF SAID LINE OF ROLLING CONTACT AND THEN UPWARDLY ACROSSSAID ADJACENT ENDS OF THE ROLLERS AT THE OPPOSITE SIDES OF SAID LINE OFROLLING CONTACT THEREBY DEFINING AN UPWARDLY OPENING RECESS BETWEEN SAIDINNER SURFACE OF THE ADJACENT END PLATE AND THE ADJACENT ENDS OF THEROLLERS SO THAT WHEN LIQUID ADHESEIVE COATING SUBSTANCE IS SUPPLIED TOTHE SPACE BETWEEN SAID ROLLERS ABOVE SAID LINE OF ROLLING CONTACT, THELIQUID COATING SUBSTANCE CIRCULATES IN EACH RECESS TO PREVENT HARDENINGOF THE COATING SUBSTANCE ON SAID ENDS OF THE ROLLERS AND SAID END PLATESAND SEALING ELEMENTS EFFECTIVELY CONTAIN THE SUPPLY OF LIQUID ADHESIVECOATING SUBSTANCE AT THE ENDS OF SAID ROLLERS.